Method of producing cellulose compounds.



ISIDO'R KIT-sen,

To all whom tit-may concern: fBe it known that I, 'Isroon Krrsnn, citizen o phia,- in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvementsin Methods of Producing Cellulose Compounds; of which {the following-is a specification.

My invention relates to an improvement in a cellulose compound useful for ars and electrlc resistance.

(1:, 'Ihe compoundsconsisting primarily of- /d1ssolved cellulose are mostly known incommeree, as celluloid, 'pyroxylin, etc.

All these compounds are-,electrically consid' ered, of low resistance when compared to rubber or gutta percha. The articles" manufactured' from same are to some extent brittle, and when subjected: to the action ofldil'utedacids, the resistance is usually greatly lessened, and these compounds are therefore not well adapted' for electrical work.

It is theo'bject of my invention to increase the reslstance'value of'such compounds and I to make such compounds toany degree of flexibility desired.- To accomplish this ob.-

ject, I have carried out in the course of shy.- eral yearsa series of experiments, and"I have produced as the-.resul't-of suchexperiments v products in the shape of jars for battery cells,

' insulating-plates, etc., which cntirel justify me in saying that the roduction o articles I from the; dissolved ce-ulose--of' different de--- grees of resistance valuesandf different de- 5 grees of flexibility is not pnly feasible,'but if the process as laid down In this my s ecification is carried .out entirely practicaii. ,j

In the course of manufacturing articles out oilsol blecellulose oi" my own make, as'well 40 as articles made ofceliuloi'd' scrap're'dissolved',

I found that it was necessary tomake these articles, mostlywhen used-as vessel's. toretain some liquid, ofeither too; great a thick ;ness oi to line the samewith acoating of rubber; r0- obviate this, to make jars and other insulating articles front-cellulose, and

to be enabled to .usethe same f'oriiisulaiiingconductors in a manner so as method of compounding thecelluloseas wili hereinaftenbe any described.

. In all compounds so far used, -tlie;cel lulose' is intermiire'd With a fibrous material in its nitrated state and I have also used asbestos aneven surface and when a plate,

-fibers for this purpose; but the products do not present or PEILADELP'iII A, PENNSYLV Specification of Letters'li'atent. Application filed'march'i, 190s. swarm, 419,745.

the United States, 'residi ng at. Phil'adeL discernible through a magnifying glass.

- pounds of the alkali should be used.

to give it the re uired liability, I have. recourse to a- MZETHQD or rnonuome GELLULOSE' coMrouNns.

Patented 0ct.;13, 1908..

made with theadditionof a fibrous material inits natural state, is broken up, the inner space of same is found to be not in a homogeneous state and the particles of cellulose, (30 surrounding the-fiber, either re tainin nearly all the cases, part of the moistureof the sol- 1 vent, or it entirely dr a space between the. same, and the other parts of the materialIis I1 most cases, the filling material for the amor phous cellulose consists of asbestos, but it is wellzknown that asbestos is evenmore hygro 'scopicztha-n theamorphous cellul'ose itself.

It is, therefore, necessary first to produce compounds which are entirely impervious to moisture and then intermix the same with the cellulose and it is also necessary to make. the cellulose, with the aid of' an additional material, impervious to moisture. r

I will now here describe'a method by which 'I- was enabled to produce jars forsecondary batteries and plates to be used as a resistance tor electric devices, and I will give, so that persons versed in the art may practice this my invention, some figures as to the proper amount of the different materials to be used in the production of the compound, but it is well understood that the ratio ofeach of thesematerials may differ to suit I requirements. 1 I V l f'it IS required to'produ'c'e the; amorphous cellulose out of a cotton fiber, it is best to ,first Was-h this fiber'in an alkali, such for instance as elgn' substances and when thoroughly washed and. then dried, itis'ready for the; nitration. Generally in the nitration, twoparts of suif'uric'acid' and onepartoi nitric acid are used,

but I have found thatif a quick nitration is. desired, it is best to use a preponderance of nitric acid and for this one thousand pounds of cotton fiber, it is preferred to use about 1 five thousand pounds of nitric acid, specific gravity I..42,-andfour thousand pounds ch11!) sulfuric acid, specific gravity. 1.84. y It has to be borne in mind that only part of aforesaid, only the nitric acid will be 'used up in the nitration and for the nextnitrating bath, it is only necessary to adda comparatively small proportion of nitric acid and sulfuric acid to the solution. I have found that of the mixture about eight hundred pounds of nitric acid and only about two hundred pounds of sulfuric acid are used up, so that for the purpose of nitrating a second lot of one thousand pounds, only a small amount of acid needs to be added to the nitrating bath.

The product, when once nitrated, should be washed repeatedly, so that no acid will remain therein. 1

- In the course of my experiments, I have found that if the nitrated cotton is subjected subsequently to a water bath containing for each one hundred gallons of water one-half a gallon of ammonia water, specific gravity 0.935, the later deterioration of the product is entirely overcome. The product should then be driedat a temperature not exceeding one hundred and ten degrees Fahrenheit (43 (1.). Y

To dissolve the nitrated product, different chemicals may be used, such for instance as acetone, amyl acetate, or glacial acetic acid; but to make the dissolving process more economical, I have recourse to the following method I place the nitrated article ina closed chamber which, in reality, may represent the receiver of a distilling apparatus, in a manner so that the fumes, passing from this apparatus through said receiver, will have to penetrate the other part of the material placed therein. This receiver is connected with a retort filled with a solvent. On the other side, the 'rec'eiveris connected, preferably, with the interposition of aworm, with a condensing reservoir. Heat is then applied to the retort and the fumes of the solvent will be carried into the receiver, will penetrate the particles of the nitrated cellulose and will dissolve the same. After the process has been carried on to a point necessary to either dissolve or only make plastic the material, the same is thentaken out and is ready tobe used with a compound later onto be described.

As stated above, either acetone, amyl acetate, or any of the well known solvents may be used. If a very weak solution of acetic acid is used in the retort (for the reason that the same can be bought very cheaply), it is best to moisten first the nitrated article, as the acetic acid fumes are, at the beginning, entirely void of any moisture. One hundred pounds of rosin (Burgundy pitch I found ver well adapted for this purpose) is then dissol ved in either acetone, or in a hydrocarbon, such as gasolene or benzene, and well intermixed with the dissolved cellulose.-

, The cellulose alone is not.well'adapted'for To produce this filler,

oo /ea the purpose of producing commercial articles and I prepare the same for such purpose by adding a compound which I call t ie tillert I preferably have recourse to the following process, taking it for granted that this filler 1s used for one thousand pounds of cotton, as aforesaid :-I take about five hundred pounds of asbestos in a state known as flour of asbestos, that is, asbestos ground fine hi0 long fibers should be present). To eliminate the hygroscopic properties, I b'oil'the asbestos flour withpreferablycastor-oil, but I have found that even the common linseed oil answers the purpose well. I found that for each pound of asbestos, a pound of oil is needed. After careful boiling, I melt separately about eighty pounds of sulfur in a manner, so that the sameshall remain in a semi-lirplid or syrupy state. The sulfur is then ar ded to the asbestos and, by reference, I add thereto about forty poun s of ammonium phosphate so as to reduce the infiammabihty of the compound when intermixed with the dissolvedcellulose. The compound is then very well intermixed so as to form a homogeneous paste. The gelatinized cotton is then intermixrh' with suitable machines, with the compound, as stated, and then with the aid of a colander rolled into sheets of the required thickness. If the mass gets too dry, aslight amount of additional solvent will bring the same tothe state of plasticity, and, if worked with due care, the mass is as plastic as sculptors clay and can be molded at leasure.

If jars are produced of these compounds, they should be dried first slowly and then at a temerature of about from one hundred and fifty to two hundred degrees C. to comlete the vulcanization. The time depends .on the thickness of the layers as well as the shape of the article, butfrom three to four days (72 to 96 hours) are generally sufficient for all practical urposes. i

It is advisabfe to dry at air temperature until the bulk of the solvent is evaporated (when the solvent is in li uid state and not the fumes of the solvent on y are used).

In case the solvent is used in a liquid state, the evaporated solvent could be condensed and recovered with economy.

I have above given proportions which I have used with satisfactory results, but it is obvious that the various proportions may differ wlthout departing from the scope of my invention.

It is only necessary to add that if the sulfur is added in too great a proportion, the res sultant article will not have the necessary strength.

Having now described my invention, what I claim as newand desire to secure by Letters Patent is z 1. The process of producing a compound consists in first producing a cellulose compound impervious'to moisture, in second,

011, and interm1xing then said fillin consists subjecting the cellulose ess whereby the same is made impervious tov pound,

producing an asbestos compound impervious to moisture, and in third, intermixmg bothcompounds .with the addition of sulfur.

2. In the production of useful articles from amorphous cellulose, the rocess, which con: sists 1n boiling the filling or such cellulose'in with said cellulose and a flour of sulfur an canizing the same with the aidof, heat.

3. The method of curing or vulcanizing articles made of amorphous cellulose, which to a procmoisture and second, to a rocess whereby the same 1s vulcanlzed w th t e ald of a sulfur. As an article of manufacture, a comthen vulconsisting of an amorphouscellulos'e,

a rosin or resin, a flour of asbestos, and oil,

cured or vulcanized with the aid of sulfur.

5. Means to produce a retainer'for liquid,

out of an amorphous cellulose, said means comprisin a dissolved rosin or resin intermixed wit said cellulose, a flour of asbestos boiled in oil, and a sulfur intermixed with said compounds.

6. As anew article ofmanufacture, a 'ar for secondar. batteries, consisting of a cellulose and a lll-ing for same, the cellulose as well as the filling made impervious to moisture, said jar Vulcanized with the aid of a sulfur. In testimony whereofI afiix my signature -1n presence of two witnesses.

V ISIDOR KITSEE. Witnesses:

EDITH. R STILLEY, MARY 0. SMITH. 

